In Olympic running events, preliminary heats are determined by
random draw, so we should expect that the ability level of runners
in the various heats to be about the same, on average. Here are the
times in seconds for the 400-meter women’s run in the 2012 Olympics
for preliminary heats 2 and 5. Use the data on the next page in
answering these questions.

Is there sufficient evidence to indicate that the variance in
running times differs among these two heats? How confident are you
in your decision?

What is the p-value for this decision? Explain its meaning in
words.

Is there sufficient evidence to indicate that the mean running
times are different for these two heats? How confident are you in
your decision?

What is the p-value for this problem? Explain its meaning in
words

Is there sufficient evidence to indicate that the variance in
running times differs among these two heats? How confident are you
in your decision?

What is the p-value for this decision? Explain its meaning in
words.

Is there sufficient evidence to indicate that the mean running
times are different for these two heats? How confident are you in
your decision?

What is the p-value for this problem? Explain its meaning in
words

Heat 2:
51.02

51.29

51.5

52.04

52.1

52.53

56.01

———-

Heat 5:

51.2

51.37

51.53

51.9

52.85

52.87

54.58